Java + Mysql UTF8 Problem

as the title said, I have a problem between java and mysql

The mysql DB, tables, and columns are utf8_unicode_ci. I have an application that took some input from an xml, then compose the query...

public String [] saveField(String xmltag, String lang){     
  NodeList nodo = this.doc.getElementsByTagName(xmltag);
  String [] pos = new String[nodo.getLength()];     
  for (int i = 0 ; i < nodo.getLength() ; i++ ) {
     Node child = nodo.item(i);
     pos[i] =  "INSERT INTO table (id, lang, value) VALUES (" +
        child.getAttributes().getNamedItem("id").getNodeValue().toString() + " , " +
        lang + " , " + 
        "'" + child.getFirstChild().getTextContent() + "'" +
        ");";       
    }   
   return pos;
}

this method return an array of String that contains one or more SQL insert Query... then

Class.forName("com.mysql.jdbc.Driver").newInstance();
con = DriverManager.getConnection("jdbc:mysql:///dbname", "user", "pass");
.....
Statement s; s =
this.con.createStatement ();
s.execute(query);

both with s.execyte and s.executeUpdate the special characters are stored as ?

so special char are not stored correctly: מסירות קצרות is stored as ?????????

Hi! is stored as Hi!

Any advice?

Thanks